Braun tube



June 20, 1939. B. WI'ENECKE 2,163,210

BRAUN TUBE Filed Oct. 9. 1936 Ja e/710 Patented June 20, 1939 UNITED STBRAUN TUBE Steglitz, Germany Application October 9, 1936, Serial No.104,862 In Germany October 14, 1935 1 Claim.

The subject matter of the invention is a method of operating cathode raytubes, more particularly for the amplification of alternating potentialsintended to act on the cathode ray, and also 5 arrangements for carryingout this method.

According to the invention, one or more of the alternating potentialsintended to act on the cathode ray are amplified and/or generated and/ormodulated and/or rectified with the aid 10 of one or more dischargepaths situated within the cathode ray tube itself.

One or more electrodes of one or more of said discharge paths may belongsimultaneously to the path of discharge serving to generate (or di- 15rectly act on) the cathode ray. In particular the amplifying path ofdischarge and the path of discharge producing the cathode ray may have acommon cathode.

Intermediate of this case and the case in which 20 the amplifying pathof discharge and the path of discharge producing the cathode ray havedifferent cathodes (which may be of advantage for some purposes forwhich the method according to the invention may be employed there is thecase 25 in which, though the cathode (heating) element is common to bothpaths of discharge, the emissive surfaces for the two paths areseparate.

In cathode ray tubes, in which the cathode serving to produce thecathode ray is arranged within an encompassing electrode (for example aWehnelt cylinder), which may serve, for example, for screening purposesand/or concentration of the ray and/or control of the intensity of theray, there may be provided within this en- 35 compassing electrode oneor more paths of discharge for amplification purposes. In a path ofdischarge provided in accordance with the invention there may beincluded in addition to the control grid one or more auxiliary grids(screen- 40 ing grid, intercepting grid, etc.), and it is also possibleto employ discharge paths of this kind in accordance with the invention,instead of for amplification purposes or in addition thereto, also forother purposes known in connection with 45 discharge tubes, for examplefor rectification, the generation of the oscillations or for modulation.In the first case, if it is desired to employ in place of an anode orgrid rectification a simple valve rectification, the path of dischargemay be made 50 bi-polar (of the diode type). According to a furtherfeature of the invention, the coupling elements necessary for thepurpose of use of the auxiliary discharge path or paths provided inaccordance with the invention may likewise be 55 arranged inside thecathode ray tube.

Two simple examples of arrangements according to the invention areillustrated in the drawing. In each figure of the drawing, there isshown merely one auxiliary discharge path arranged according to theinvention, via, a three pole amplifying path, serving in thearrangements shown in Fig. l for the amplification of deflectingpotentials, and in Fig. 2 for the amplification of intensity controlpotentials.

The coupling elements are shown in all figures as being provided withinthe cathode ray tube.

In the drawing l is the bulb of the tube, 2 the cathode member havingthe emissive surface 3 serving to produce the cathode ray, 4 anencompassing electrode, 5, 6 and l are additional electrodes which actas accelerating electrodes and/or elements of the electronopticalarrangement, 8 and 9 are deflecting electrodes, and Ill (in Figs. 1 and2) is an emissive surface which is acted upon by the same heatingelement as 3 and belongs to the path of discharge serving foramplification purposes. H is the appertaining anode, and [2 (in allfigures) is the control grid provided in the auxiliary path ofdischarge;

I3 is a luminescent screen structure shown as being of the well knownconventional type; the leads K, H, W, A1, A2 and G serve for supplyingthe heating (preferably alternating) potential, the direct potentialsfor the system electrodes and the alternating potentials to beamplified. The amplified alternating potenials are tapped at the anoderesistance Ra and by way of the coupling condenser C are conducted inthe arrangements according to Fig. 1 to a deflecting plate and in thearrangement according to Fig. 2 to the encompassing electrode (Wehneltcylinder). H

is the leak resistance for the electrode to which the amplifiedpotential is conducted.

In Figs. 1 and 2 the auxiliary path of discharge has a specialcathode-emission surface which, however, is provided on the same cathode(heating) element as the emissive surface serving to produce the cathoderay. The entire auxiliary path of discharge is provided within theencompassing electrode 4.

The lead P in Fig. 2 serves for supplying the deflecting alternatingpotentials.

Naturally the method according to the invention may also be applied tocathode ray tubes of greatly varying construction and for the mostdifferent purposes, including more particularly those Braun tubes whichare employed for oscillographic, television or sound-film purposes.

I claim:

In a cathode ray tube comprising a beam gun as anode, beam deflectingplates and an inside heated cylindrical insulator supporting the raycathode and being surrounded by a cylindrical electrode, said insulatorsupporting a second cathode forming, in cooperation with a cylindricalgrid and a cylindrical anode arranged inside of said cylindricalelectrode, a thermionic amplifier, said both cathodes being connectedwith each other and said cylindrical anode being connected through ananode resistance arranged inside of said cathode ray tube to said beamanode, and through a condenser being arranged inside of said cathode raytube to one of said deflecting plates, said grid being adapted to beconnected to the scanning potential.

BRUNO WIENECKE.

